Does anyone out there know anything about bead blasting?

F

fordf250

Joined
May 6, 2007
Messages
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I have asked this question on the maintenance forum and it looks like no one has any information about the use of bead blasting in the knife world. I know some of the manufacturers use it on their blades as a surface treatment, but I'm not really sure why they do. Is it aesthetics or utility? (i hope i spelled that correctly)

I acquire old knives of all kinds and modify & refurbish them for the fun of it. I was thinking I could buy a small "pencil blaster" and use it to clean them up, apply a different finish or perhaps do some scroll work. Before I spend the $$$$ to buy one I am interested in some idea how this may or may not work out.

Has anyone had any experience using one on knives? On ANYTHING? Thanks...
 
Never done it myself, but i looked into giving it a try.

you'll need:

1. blast cabinet,
2. air compressor,
3. blast gun,
4. various media in different coarseness,
5. practice blades.

a bb finish is very durable and doesn't show scratches nearly as easily as a satin or polish. it can also be easily redone.
 
You could probably get away with

air compressor (20cfm+ best but as low as 5cfm)
siphon feed media blaster
media
container

The biggest key factor is having a place where you can either collect the media, like use a large plastic container (rubbermade is good quality) and havea way to hold the knife blade.

mori has the fool proof setup listed.
 
harbor freight has pretty much everything.

not the best quality, but inexpensive and as long as you aren't making it a full time career, their stuff should suit you fine.
 
flame me if im wrong, but i think bead blasting is the modern version of peening - where a metal was hit over and over with a ball-peen hammer. think it compresses the metal, and was used to give, not a pretty, but a harder finish. saying that, i will be the first to point out i have never done it

http://en.wikipedia.org/wiki/Peening
 
I've never done it but have heard (on the forum) that the finish is more prone to rust than many others because of the way it retains moisture. Tumbling is more popular as a durable, non-marking finish.
I prefer the look of a polished blade, even if satin finished, but they are considerably more labour intensive if done by hand.
Greg
 
swordofthesavior said:
flame me if im wrong, but i think bead blasting is the modern version of peening - where a metal was hit over and over with a ball-peen hammer. think it compresses the metal, and was used to give, not a pretty, but a harder finish. saying that, i will be the first to point out i have never done it

http://en.wikipedia.org/wiki/Peening
Click to expand...

I would like to correct you if I may, peening and bead blasting are not the same,peening work hardens the surface and bead blasting removes some of the surface material.There is a treatment we use on some aircraft parts called shot peening ,small balls propelled by compressed air toughen up the surface much like the old hammer method.
 
In my experience, bead blasted blades are quite prone to rusting.

I've got several folders with bead blasted blades that I rarely carry because a sweaty hand is enough to make the blade rust. As a user, I HATE this sort of finish. My carbon steel pocket knives fare better than those with bead blasted blades!
 
I have asked this question on the maintenance forum
Click to expand...

Okay, let's try Shop Talk.

I know some of the manufacturers use it on their blades as a surface treatment, but I'm not really sure why they do. Is it aesthetics or utility? (i hope i spelled that correctly)
Click to expand...

I think it's mostly because it's a cheap way to finish a knife, but some people like the way it looks, too....
moving-van.jpg
 
Having been a metal fabricator and having worked around a lot of blasting here is my take. Steel shot gives the most "profile" followed by sand, then glass and starblast (actually a type of slag or cinder) then walnut hulls. Profile is how much displacement occurs when the medium hits the object to being blasted. Think of the surface as being cratered. The hardness, weight and shape of the blast media effects the shape of the tiny craters. The great thing about a heavy profile is its ability to hold a coating (paint etc). But, un covered or protected the outside edges of the craters can easily rust due to increased area exposed to moisture and oxygen. Walnut hulls will remove most most rust and other dirt with out much effect on steel with any thickness at all.
 
Thanks for the interesting comments. I have a much better idea what I will be getting into... yes, I think I will venture forth.

I was wondering why MORI didn't follow through and do some blasting? I also checked Harbor Freight online and they only had a couple bags of blasting sand. I did get some good leads googling.

I hadn't thought of the rust factor. Yeah, makes sense. ib2v4u helped a lot with understanding the blast media. I'm sure I will have a bag of walnuts handy to get around some of the rust issues.

I also picked up somewhere that the "craters" created by blasting are desirable in some kitchen knives, especially thoses used for slicing. Seems the knife slices thru only on the "rim" of the craters which lessens the surface tension considerablly. Sounds logical if only a fraction of the blade surface touches the item being sliced. Can anyone verify this concept?

Maybe I should look into coatings once I get this phase done... Yikes, I just thought of Hi-Temp Engine Block Spray Paint!
 
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